This section provides background information to facilitate a better understanding of the various aspects of the disclosure. It should be understood that the statements in this section of this document are to be read in this light, and not as admissions of prior art.
Welding and cutting equipment typically utilizes hoses for making connections between a torch and regulators. The hoses must be strong, nonporous, light, and flexible enough to make torch movements easy. The hoses are typically made to withstand internal pressures that can reach as high as 174 psi.
Such hoses are typically available in single- and double-hose lengths. Size is determined by the inside diameter, and the proper size depends on the type of work for which it is intended. Hose used for light work has a 3/16 or ¼ inch inside diameter and one or two plies of fabric. For heavy-duty welding and cutting operations, use a hose with an inside diameter of 5/16 inch and two to four plies of fabric. Single hose is available in the standard sizes as well as ½ and ¾ inch sizes. These larger sizes are for heavy-duty heating and for use on large cutting machines.
The most common type of cutting and welding hose is the twin or double hose that consists of a fuel hose and an oxygen hose joined together side by side. They may be joined together by either a special rib or by clamps. Because the hoses are joined together, the hoses are less likely to become tangled and are easier to move from a first place to a second place.
The length of hose may also be important. The delivery pressure at the torch varies with the length of the hose. A 20-foot, 3/16-inch hose maybe adequate for a job, but if the same hose was 50 feet long, the pressure drop would result in insufficient gas flow to the torch. Longer hoses require larger inside diameters to ensure the correct flow of gas to the torch. The hoses used for fuel gas and oxygen are often, but no always, identical in construction, but they differ in color. This color coding aids in the prevention of mishaps that could lead to dangerous accidents.
The conventional hoses are nitrile rubber (NBR)/styrene-butadiene rubber (SBR) based hoses that are often insufficient in chemical resistance, and thus unable to fulfill the requirements of some testing standards. One such standard is the Australian Standard AS1335 for hose and hose assemblies for welding, cutting and allied processes. This standard sets out requirements for hose and hose assemblies for use in the welding, cutting and allied processes. The hose and hose assemblies have a minimum rated working pressure of 1.2 MPa for containing and conveying acetylene, oxygen, liquefied petroleum gases (LPGs) and mixtures of methylacetylene and propadiene (MPS), nitrogen and other non-combustible inert shielding gases such as argon and carbon dioxide. The standard requires the hoses to pass rigorous exposure to chemicals, such as methyl borate, acetone and pentane.
Thus, there exists a need for combinations of materials which form articles, such as welding and cutting equipment hoses which have sufficient chemical resistance required by certain standards, such need met at least in part, with the following disclosure.